Rotary web press



Oct. 30, 1934. 0. c. F. MEISEL 1,978,715

ROTARY WEB mass Filed Feb. -16. 195s 2 Sheets-Sheet 1 Oct. 30, 1934. o,c, F, MEISEL 1,978,715

ROTARY WEB PRESS Filed Feb. 16, 1933 2 Sheets-Sheet 2 Patented 0.1.30,1934 UNITED STATES PATENT orrica 3 Claims.

This invention relates to rotary presses and the object" is to providea'web press which will print on the web an immediate succession ofimpressions of less length than the circumference of the plate cylinderor cylinders. The web thus may be completely imprinted without waste andbe cut into sheets of correspondingly short length, folded or otherwisedisposed of as may be desired. I obtain this result by the use of asuitable looping mechanism which is readily adjustable to provide forthe printing of different sized sheets.

My invention wlllbe well understood by reference to the followingdescription of the illustrative embodiment thereof shown by way ofexample in the accompanying drawings, wherein:--

Fig. 1 is a diagram of the press;

Fig. 2 is a broken fragmentary view of the mechanism for operating thelooper rolls; and

Fig. 3 is-a diagram corresponding to part of Fig. 1 and showing amodification.

Referring to Fig. 1 of the drawings, I have there shown a. rotary pressembodying a plurality of printing couples comprising the plate cylinders5 and impression cylinders 7. The web w drawn from a suitable supply isfed thereto by feed rolls 9 over fixed roll 11, movable looper roll 13carried on the reciprocating frame 15, andflxed roll 17, leads thencethrough the printing couples, and leaves the latter over fixed roll 19,movable looper roll 21 carried by frame 15 in fixed relation to looperroll 13, fixed roll 23, and feed rolls 25 which operate in synchronismwith'feed rolls 9.

The feed rolls 9 and 25 may be suitably driven,

as, for instance, by means of change gears to left in Fig. 1, roll 21will draw through the couples slack released by the movement of. theroll 13 so as to permit the web to pass through the couples during theprinting operation at the same surface speed as the form. After printingis finished and while the web is no longer gripped between the formcylinder and the impression cylinder, movement of the looper rolls tothe left may be retarded. They may then be moved back to the right sothat roll 13 draws back the web through the forms and also takes up theweb which is meanwhile being supplied by the rolls 9 while roll 21 givesup slack to permit the retraction of the web through the forms and topermit the continued operation of the feed rolls 25, delivering the webfrom the press at a constant speed. At the end of this retrogrademovement the looping rolls may move to the left once again, graduallyaccelerating the paper extending between them to the speed of the platecylinder so that when the latter again starts to print, blank paperimmediately behind the part previously printed is presented to the form.

Looping mechanism operating generally in the manner above described isdisclosed in the patent to Annand 834,602, Oct. 30, 1906, and does notneed extensive description. The arrangement there shown, however,requires the use of separate cams for operating the loopers for eachsheet length printed and provides for advancing the sheet at a uniformspeed by the joint action of the feed rolls and the looper rolls duringsuch fraction of the revolution as is equal to a fraction whosenumerator is the sheet length and whose denominator is the cylindercircumference. In contrast therewith I provide a single cam inconnection with which an exceedingly simple adjustmizeent provides forhandling a wide range of sheet s s.

I will first describe in a general way the mechanism shown withoutreference to its theory of operation. Herein the looper frame 15 (seeFig. 2) carries a rack 27 with which meshes a sector 29 operated by apitman 31 which is oscillated by groove cam 33 which makes onerevolution for each revolution of the press. The pitman 31 has anadjustable crank connection with the sector 29, the latter being hereshown with a slot 35 along which the end of the pitman may be slidablyadjusted to be clamped by the clamp screw 37.

In accordance with my invention 1 provide for a uniform advance of theweb by the looper rolls during a fixed fraction of the revolution of theplate cylinders while the construction is such as to permit the handlingof sheets of any length equal to or less than the product of thisfraction and the cylinder circumference without changing the machineother than by a simple and readily made adjustment and the necessarychange in speed of the feed rolls 9 and 25 to permit them to feed in andout the desired length of sheet.

By way of example and to illustrate one practical construction we maytake as this fixed fraction of the circumference of the cylinder, thearrangements then permitting printing a sheet of this or any shorterlength. I preferably provide an excess feeding movement to insure thatno change of paper speed will occur while the web is gripped by theplate cylinder and for that reason may utilize 260 of the revolution forfeeding the paper at the surface speed of the plate cylinders. Thisprovides for 4 at either end which may be considered excess feed. Theremaining 100 of a revolution may then be utilized to stop the sheet, toretract it and again to reverse its motion, and conveniently, as in theexample herein chosen for illustration, 60 of the revolution may beutilized for retracting movement corresponding to a movement of therolls 13 and 21 to the right in Fig. 1 and 40 to the reversals ofmovement suitably arranged to prevent shock.

Thus referring to the cam shown in Fig. 2 (the possibility of cuttingsuch a cam will be shown by the analysis to follow later), the arc ab cdmay be a smooth spiral corresponding to an advance of the looper rollsto the left at uniform speed. a-b, 4 in extent, represents an idlemovement or overfeed before the plate cylinder begins to act. The are bcis 252 long and during this time printing takes place. Overfeed of 4 isprovided at cd. I here show are de as 10 in extent. This period isutilized in reversing the rolls and may, if desired, provide for aretarded movement to the left and/ or preferably includes a substantialperiod of dwell at the extreme of movement to permit absorption ofinertia. The are e---), 60 in length, provides for retracting the paper.Arc f--a, 30 in length, provides for reversal with the rolls moving tothe right again preferably with a substantial dwell and, if desired,with subsequent acceleration to the left. Since the movement of therolls to the left is slower than the movement to the right, are de mayconveniently as here be shorter than are fa and the period of dwell maybe shorter. It should be understood that on account of the small scaleof the drawing it represents only in a very general way the cam contour.

The arrangement may be best understood by considering first the lengthof paper moved independently of speed. For convenience in the discussionwe may denote the circumference of the plate cylinder as C and thelength of paper or sheet length delivered by the rolls 9 and 25 as S.During the 260/360 of a revolution, therefore, the feed rolls deliver alength of paper equal to 260/360 S and, if it is desired to move thisthrough the couples at the same linear speed as the surface speed of theplate cylinder, the length of paper passing through the couples must be260/360 C. and the movement of looper roll 21 to the left must then drawthrough the couples a length of paper equal to 260/360 (CS). Similarlyin any retarding movement previous to retraction of the web and whilearc de of the cam is acting, the looper may draw paper equal in lengthto P at any suitable variable speed, and similarly if acceleration isprovided in the arc fa the rolls may draw forward a length Q. The totalexcess movement due to the operation of the looper roll is therefore260/360 (CS) +P+Q. The linear movement of the roll on the frame 15 dueto the fact that it operates on the bight of a loop isone-half 01' this.

Now, referring to Fig. 2, if the throw of cam 33 is t and the pitchradius of segment 29 is 10 inches, the effective crank arm a: by meansof which pitman 31 must act on the'segment deflning the position ofconnection 37 along slot 35 is determined by the following proportion:

10 i: Now for any given machine all these terms are constants except thesheet length S and for any value of S, that is, for any given sheetlength, will correspond a value of :c, that is, a definite position ofpoint of connection of the pitman to the sector which will provide for aproper advance of the looping rolls.

The description thus far has been primarily of the action of the'webduring 260 of the revolution of the plate cylinder or 260 of therevolution of the cam 33 during the feeding action of the latter. Thenet desired result of the cooperating action of the feed rolls and thelooper rolls is to pass through the couples a sheet length S on eachrevolution. There passes forward through the couples during theadvancing feed a length of web equal to 260/360 C. The sheet length Shas been usefully utilized to receive an impression. We must draw back260/360 CS. During the remaining 100 of the circumference, if anydeceleration or acceleration is provided while the loopers still move tothe right, the length P-i-Q is drawn through. Moreover, during this 100/360 of a revolution the feed rolls 9 will deliver 100/360 S. We mustdraw back, therefore, the sum of these quantities, which is 260/360(CS)+P+Q, and the linear motion of the looper roll frame is one-half ofthis. This movement, it will be seen, is identical with the feed motionof the looper rolls. The cam connection 37 remains in the same positionalong the slot 35 and the path of the cam returns on itself.

Thus by way of example, if we assume a plate cylinder of 4 inch diameteror l4.92 inches circumference, a throw of 1.4375 inches along arc abcdof cam 33 (that is, omitting any portion of the throw which may beincluded in arcs d-e or ,f-a to efiect the retarding and acceleratingfeeding movements P and Q or alternatively assuming these values to bezero and the arcs d-e and f-a to be circles calling for a dwell of thelooper rolls throughout their length) and if we assume a pitch radius of10 inches for segment 29, then the distance a: of the point ofconnection 37 from the center of motion of the sector for a 7 inch sheetlength may be computed from the simplified formula as 5.025 inches and atable might be compiled for other lengths up to .7 of the cylindercircumference, that is, approximately 10% inches. For a fullcircumference sheet the segment would be clamped stationary.

As a specific example and assuming the plate cylinder 14.92 as abovementioned and a sheet length of '7 inches, the head of the sheet arrivesat the form and for 252/360 of a revolution moves a distance of 10.444inches while the cam follower travels from b to c. From 0 to d themovement continues as an overfeed of .166 inches independent of thesheet length. The head of the sheet may then continue to advance at avariable speed to a distance of P+.l94 inches, that is, P+10/360 S,depending upon the design of the cam, and while the cam follower travelsfrom d to e. During the following 60 the web is fed forward 1.167 inches(60/360 S) by its feed roll. At the same'time it is drawn backward bythe action of the looper rolls 5.72+P+Q inches, which may be considereda negative number. Then between points f and a on the cam the web movesforward again .583 inches, that is,

- Q+30/360 S. Finally between a and b there is a forward movement of.166 inches. The algebraic sum of these quantities is seen to be 7'inches so that at the completion of the cycle the head of the sheet has.moved just 7 inches past the bite of the printing rolls and the blankpaper immediately following the impression on that sheet is presentedready to be printed on.

In cases oi very short sheet lengths it is advantageous to use a doubleloop, as indicated in Fig. 3, in which the paper leading from'flxed rollllfpasses over a movable looper roll 13a, hence to a flxed roll 14, backto looper roll 13b, both looper rolls being carried on the reciprocatingframe 15, and hence to fixed roll 17 and similarly at the other side ofthe press. The motion of the looping roll frame is in this instance y.of the paper feed eflected thereby and the momentum or inertia of themotion is thus diminished. Again in the case of a dimension of a '1 inchsheet, if a double loop is utilized, the lever arm through which thepitinan 31 acts on sector 29 would be 10.052 inches. Further advantagein double looping is that it keeps the point of connection of the pitmanto the segment within a range where better leverage is secured and notwithin shorter lengths where any error is multiplied in the segment.

I am aware that the invention may be embodied in other, specific formswithout departing from the spirit or essential attributes thereof, and Itherefore desire the present embodiment to be considered in all respectsas illustrative and not restrictive; reference being had to the appendedclaims rather than to the foregoing description to indicate the scope ofthe invention.

I claim:

1. In a press in combination with rotary printing means. means forfeeding a web to and from the same at speeds less than they surfacespeed of the plate cylinder, looping mechanism, driving means foreffecting during a revolution of the cylinder a uniform motion in onedirection and an intermediate retracting motion, and ad- Justableimeansfor transmiting said motion in desired ratio to the looping mechanism.

2. In a press in combination with rotary printing means, means forfeeding a web -to and from the same at speeds less than the surfacespeed of the plate-cylinder, looping rolls, a rack carrying the rolls,a" sector meshing with the rack,

a cam rotating in synchronism with the plate cylinder having a spiralarc and an intermediate node and a crank arm connection of adjustablyvariable length between the cam andjthe sector. 3. In a press incombination with rotary print ing means, means for feeding a web to andfrom the same at speeds less than the surface speed of the platecylinder, a reciprocable frame having having pairs of rolls thereon,cooperating fixed rolls to permit the web to be trained in a plu- Vrality of loops, and means for moving the frame comprising a cam'and alever transmission of adjustable length. I

v OTTO. C. 1". MEISEL.

